We will now go a step further and turn from “acute” combinations to such combinations as are, as it were, impending. Here, too, I urgently recommend beginners (advanced players do it as a matter of course) to proceed by way of simple arithmetical calculations, but, instead of enumerating the attacking and defending pieces, to count the number of possibilities of attack and defence.
Let us consider a few typical examples. In Diagram 9, if Black plays P-Q5, he must first have probed the position in the following way. The pawn at Q5 is attacked once and supported once to start with, and can be attacked by three more White units in three more moves (1. R-Q1, 2. R(B2)-Q2, 3. B-B2) Black can also mobilise three more units for the defence in the same number of moves (1. Kt-B4 or K3, 2. B-Kt2, 3. R-Q1). There is, consequently, no immediate danger, nor is there anything to fear for some time to come, as White has no other piece which could attack the pawn for the fifth time.
Diag. 9
It would be obviously wrong to move the pawn to Q6 after White’s R-Q1, because White could bring another two pieces to bear on the P, the other Rook and the Knight, whilst Black has only one more piece available for the defence, namely, his Rook.
The following examples show typical positions, in which simple calculation is complicated by side issues.
In Diagram 10, the point of attack, namely, the Black Knight at KB3, can be supported by as many Black units as White can bring up for the attack, but the defensive efficiency of one of Black’s pieces is illusory, because it can be taken by a White piece. The plan would be as follows: White threatens Black’s Knight for the third time with Kt-K4, and Black must reply QKt-Q2, because covering with R-K3 would cost the “exchange,” as will appear from a comparison of the value of the pieces concerned. The “exchange” is, however, lost for Black on the next move, because
Diag. 10
White’s further attack on the Knight by Q-B3 forces the Rook to defend on K3, where it gets into the diagonal of the Bishop, which at present is masked by White’s Knight. The sequel would be 3. QKtxKtch, RxKt (not BxKt on account of BxR winning a whole Rook), 4. BxR, and so on. A similar case is shown in Diagram 11.